Cost of Eastside bus plan cut

Sound Transit reduces estimate by $2 billion for alternative

By JANE HADLEY, SEATTLE POST-INTELLIGENCER REPORTER

Published 10:00 pm, Thursday, May 12, 2005

Accused by their critics of a bias in favor of light rail, Sound Transit staff members responded yesterday by releasing significantly revised cost figures for transit across Interstate 90 to the Eastside.

The revision also fixed what the agency said was an innocent mistake.

The result was a $2 billion reduction in the cost of a bus alternative for serving the Eastside.

The alternative would use buses in existing car pool lanes on freeways to link Eastside cities to each other and to Seattle's light rail system. It would also involve the building of new ramps connecting car pool lanes on Interstate 405 directly to car pool lanes on I-90 and state Route 520.

The estimated cost of the bus alternative -- most of which would go for the costly connector ramps -- is now $2.5 billion to $3.5 billion. It would attract an estimated 30,000 riders a day.

In comparison, a light rail alternative from downtown Seattle would cost an estimated $2.3 billion to $4.4 billion, depending on whether the light rail line stopped at Overlake or continued to Redmond.

The cost also depends on whether light rail goes to downtown Bellevue via a tunnel or an elevated structure.

The light rail ridership is estimated at 42,000 to 44,000 a day. Light rail attracts more passengers than do buses, because trains could carry passengers all the way from the Eastside to downtown, the University of Washington or Northgate without requiring a transfer. Also, the trains, which would be completely separated from traffic, would travel faster than buses.

Next month, the Sound Transit board is to adopt a 30-year plan for expanding its current system. In the fall, the board will select specific 10- to 15-year projects to take to voters, probably in the fall of 2006.

The next major project the agency has said it will pursue is one that would connect the Eastside into Seattle's light rail system. But it needs to decide whether to do that with buses or rail.

The reason for the $2 billion revision for the bus alternative is twofold. First, the agency bowed to questions raised by the state-appointed Expert Review Panel concerning the pricey connector ramps. Sound Transit had originally charged the entire cost of rebuilding the 405 interchanges with 520 and I-90 to the bus alternative. Critics said buses between Seattle and Overlake would use only one ramp at each of the two interchanges and that buses should not be charged for building eight ramps when only two were needed. That saved about $1 billion.

The other $1 billion in savings came from correcting a misunderstanding over cost estimates for the ramps. Sound Transit thought the estimates from the state Department of Transportation were in 2004 dollars and needed to be inflated to 2005. Instead, the estimates were in later-year dollars that needed to be deflated to 2005.

They've said the light rail line on I-90 will get many of its riders by attracting them away from buses on the state Route 520 bridge. To properly compare bus and rail for serving the Eastside, says former Boeing manager Richard Harkness, Sound Transit needs to look at all trips from the Eastside to Seattle -- across both 520 and I-90.

Sound Transit's own figures show that daily transit volumes between Seattle and the Eastside for I-90 and 520 combined would be 69,100 for buses compared with 70,100 for light rail.

That's roughly the same ridership, yet buses are less expensive, Harkness said in a recent letter.

Under questioning yesterday from King County Councilwoman Julia Patterson, who is also a Sound Transit board member, Sound Transit Planning Director Paul Matsuoka said there factors affecting the comparison that do not show up in the ridership forecasts. The forecasts are based on a model that must pass federal muster.

Most important, the model assumes that buses in car pool lanes will always travel 45 miles per hour even though experience has shown that buses do not reliably travel 45 mph during rush hour.

"With light rail, that predictability is there," Patterson said.

The model also assumes people have no preference between buses and rail, though Sound Transit's experience has been that people prefer rail.

A free bus line in downtown Tacoma attracted 400 to 500 riders a day. The first day it was replaced with a light rail line, ridership zoomed to 2,400 a day and has gone up since, Matsuoka said.

The model also allows no assumption that rail stations would spur development around them, upping ridership.

With only two corridors across a 20-mile-long lake, it's important to "maximize throughput," Matsuoka said.